Rotor mechanism of rotating electrical machine and method of manufacturing same

ABSTRACT

In a rotor mechanism of a rotating electrical machine, a crimp groove is formed, in a circumferential direction, in an outer circumferential portion of any one of the end plates of a rotor shaft on an outside in the axial direction. The one end plate is located in the axial direction by an inside end of a crimp retainer in the axial direction that is ring-shaped, that covers the crimp groove of the rotor shaft to fit to the rotor shaft, that is fitted into the crimp groove of the rotor shaft by crimping an outside portion in the axial direction from an outer circumferential side and that engages with a wall surface of the crimp groove on the outside in the axial direction.

TECHNICAL FIELD

The present invention relates to a rotor mechanism that functions as arotor or an armature of a rotating electrical machine such as anelectrical motor and a method of manufacturing such a rotor mechanism,and more particularly relates to a rotor mechanism of a rotatingelectrical machine suitable for fastening a core and a shaft and amethod of manufacturing such a rotor mechanism.

BACKGROUND ART

JP2006-187063A discloses, as a fastening mechanism of a core and a shaftin which a large number of electromagnetic steel sheets constituting arotor of a rotating electrical machine are stacked in layers, afastening mechanism in which end plates arranged on both side surfacesof the core are directly pressed into the shaft and fixed thereto.

This is achieved by a mechanism in which a collar is interposed betweenthe core and the shaft that are constituent elements of the rotor and inwhich the shaft and the collar, and the collar and core are pressed andfastened with a predetermined clearance. On both side surfaces of thecore, the end plates directly pressed into the shaft are arranged. Whenthe core and the end plates are formed with a silicon steel sheet andthe shaft is formed with a steel rod, the collar is formed of anon-ferrous metal material such as a magnesium alloy that has a higherlinear expansion coefficient than at least the core and the shaft. Thus,even if the individual elements are thermally expanded under a hightemperature environment, a clearance of the collar with respect to theshaft in a direction in which a diameter is reduced is acquired.

SUMMARY OF THE INVENTION

However, in the conventional example described above, the end platesarranged on both sides of the core are directly pressed and fixed intothe shaft. Hence, disadvantageously, in a case where the outsidediameter of the shaft is large, variations in the inside diameter of theend plates and in the outside diameter of the shaft produced when theend plates are pressed into the shaft easily cause variations inpress-in force (the force holding the end plates), and they come offdepending on the situation.

The present invention is made in view of the conventional problemdescribed above. An object of the present invention is to provide arotor mechanism of a rotating electrical machine suitable for fasteninga core and a shaft and a method of manufacturing such a rotor mechanism.

According to one aspect of the present invention, there is provided arotor mechanism of a rotating electrical machine that supports andincludes a core obtained by stacking a plurality of disc-shaped magneticsteel plates on an outer circumference of a rotor shaft and disc-shapedend plates arranged on both sides of the core in an axial direction.

In the present invention, in the rotor shaft, a crimp groove is formed,in a circumferential direction, in an outer circumferential portion ofany one of the end plates on an outside in the axial direction. The oneend plate is located in the axial direction by an inside end of a crimpretainer in the axial direction that is ring-shaped, that covers thecrimp groove of the rotor shaft to fit to the rotor shaft, that isfitted into the crimp groove of the rotor shaft by crimping an outsideportion in the axial direction from an outer circumferential side andthat engages with a wall surface of the crimp groove on the outside inthe axial direction.

Embodiments of the present invention and advantages of the presentinvention will be described in detail below with reference toaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a rotor mechanism of arotating electrical machine showing an embodiment of the presentinvention;

FIG. 2 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine;

FIG. 3 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine, subsequent to FIG.2;

FIG. 4 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine, subsequent to FIG.3;

FIG. 5 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine, subsequent to FIG.4;

FIG. 6 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine, subsequent to FIG.5;

FIG. 7 is an illustrative diagram showing a step of manufacturing therotor mechanism of the rotating electrical machine, subsequent to FIG.6;

FIG. 8 is a partial cross-sectional view of a crimp retainer used;

FIG. 9 is a perspective view showing an example of the crimp retainer;

FIG. 10 is a perspective view showing another example of the crimpretainer;

FIG. 11 is an illustrative view showing shapes (A) and (B) of the crimpretainer after crimping;

FIG. 12 is a schematic configuration diagram of a rotor mechanism of arotating electrical machine showing a second embodiment of the presentinvention;

FIG. 13 is a cross-sectional view of a crimp retainer;

FIG. 14 is a cross-sectional view of the crimp retainer in a compressedstate; and

FIG. 15 is a schematic configuration diagram of the rotor mechanism ofthe rotating electrical machine showing one aspect where the crimpretainer is elastically deformed.

DESCRIPTION OF THE EMBODIMENTS First Embodiment

FIG. 1 is a cross-sectional view showing an embodiment of a rotormechanism of a rotating electrical machine according to the presentinvention. In FIG. 1, the rotor mechanism of the rotating electricalmachine includes a cylindrical core 1, disc-shaped end plates 2 and 3arranged on both sides of the core 1, a rotor shaft 4 that insertsthrough and supports the core 1 and the end plates 2 and 3, and a crimpretainer 5 that locates and fixes the core 1 and the end plates 2 and 3on the rotor shaft 4.

The rotor shaft 4 is cylindrical, includes, in an inner circumferentialportion of a cylindrical portion, a flange 41 extending in an innercircumferential direction, is fastened through the flange 41 to anunillustrated drive shaft and is formed rotatably together with thedrive shaft. The outside diameter of the rotor shaft 4 is formed to besubstantially equal to the inside diameter of the core 1. In an outercircumferential portion of a region of the rotor shaft 4 supporting thecore 1 on one side in the axial direction, a protrusion portion 42 thatsupports the end plate 3 on the other side is formed around the entirecircumference. In the outer circumferential portion of the region of therotor shaft 4 supporting the core 1 on the other side in the axialdirection, a crimp groove 43 engaging with the crimp retainer 5 isformed around the entire circumference. The crimp groove 43 may not beprovided on the entire circumference, and may be provided partially inthe circumferential direction. In the example shown in the figure, theouter circumferential portion of the rotor shaft 4 has a smallerdiameter outwardly of a portion (away from the support region of thecore 1) where the crimp groove 43 is arranged.

The protrusion portion 42 is formed in a stepped shape with asmall-diameter portion 44 and a large-diameter portion 45. Thesmall-diameter portion 44 is adjacent to the region supporting the core1 and protrudes from the outer circumferential portion of the rotorshaft 4 to the outer circumference in the radial direction, thelarge-diameter portion 45 is formed to protrude, in an outsideconnecting (away from the support region of the core 1) to thesmall-diameter portion 44 in the axial direction, from the outercircumferential portion of the rotor shaft 4 to the outer circumferencein the radial direction.

The core 1 is formed such that, for example, a shaft insertion hole 11is formed in the center portion of a circular magnetic steel plate madeof magnetic material, and that a plurality of magnetic steel plates areintegrally stacked in layers by crimp processing or the like.

In an inner-diameter portion of the disc-shaped end plate 3 on the otherside, a stepped hole 32 composed of a small-diameter hole 34 fitting tothe small-diameter portion 44 of the protrusion portion 42 and alarge-diameter hole 35 facing the large-diameter portion 45 of theprotrusion portion 42 is formed. As shown in FIG. 2, in the end plate 3on the other side, the small-diameter hole 34 of the stepped hole 32 isfitted to the small-diameter portion 44 of the stepped protrusion 42 ofthe rotor shaft 4, and a stepped portion between the small-diameter hole34 and the large-diameter hole 35 makes contact with a stepped portionbetween the large-diameter portion 45 and the small-diameter portion 44of the stepped protrusion in the axial direction, and thus are supportedby the protrusion portion 42 of the rotor shaft 4.

As also shown in FIG. 3, in the end plate 3 on the other side, the core1 formed with the disc-shaped stacked steel plates is fitted to theouter circumferential portion of the rotor shaft 4, and they are stackedin the axial direction.

In an inside-diameter portion of the disc-shaped end plate 2 on the oneside, a stepped hole composed of a small-diameter hole 21 arranged on aside in contact with the core 1 and a large-diameter hole 22 arranged onthe side opposite to the side of the core 1 is formed. As also shown inFIG. 4, the end plate 2 on the one side has the small-diameter hole 21of the stepped hole fitted to the outer circumferential portion of therotor shaft 4, is stacked from the other side of the core 1 in the axialdirection and is supported by the rotor shaft 4.

As shown in FIG. 8, the crimp retainer 5 is formed with a ring-shapedportion 51 which is formed with a ring-shaped flange portion 52 and aring-shaped sleeve portion 53, whose cross section is formed in theshape of an L and which is formed in the shape of a disc and a crimppart 54 which protrudes from the sleeve portion 53 in the axialdirection and is deformed by crimping. The sleeve portion 53 and thecrimp part 54 are formed to fit to the outer circumference of the rotorshaft 4, and the sleeve portion 53 is fitted to the rotor shaft 4 andthus is located in the radial direction with respect to the rotor shaft4.

In the ring-shaped portion 51 of the crimp retainer 5, its cross sectionis formed in the shape of an L with the flange portion 52 and the sleeveportion 53 such that shape rigidity, that is, bending rigidity withrespect to a flat surface perpendicular to the shaft is acquired by thesleeve portion 53 and circular rigidity is acquired by the flangeportion 52.

As shown in FIG. 5, the crimp retainer 5 is fitted from the side of thecrimp groove 43 to the rotor shaft 4, and is, as shown in FIG. 6,brought into contact with the stepped portion between the small-diameterhole 21 and the large-diameter hole 22 of the end plate 2 on the oneside of the flange portion 52. Then, a pressure is applied from the sideof the crimp retainer 5 in the axial direction such that a constantpre-pressure (pre-load) is applied to the end plate 3, the core 1 andthe end plate 2 arranged between the crimp retainer 5 and the protrusionportion 42 of the rotor shaft 4.

Thereafter, as shown in FIG. 7, the crimp part 54 of the crimp retainer5 is bent by crimp processing from the outer circumference into thecrimp groove 43 inwardly in the radial direction, thus is fitted intothe crimp groove 43 and is located with respect to the rotor shaft 4 inthe axial direction. Then, in the crimp retainer 5, the bending end ofthe crimp part 54 is pressed onto the wall surface of the bottom portionof the crimp groove 43, is prevented from being moved outwardly in theaxial direction and is strutted, and thus it is possible to locate andfix the crimp retainer 5 on the rotor shaft 4 with the pre-pressure keptapplied to both the end plates 2 and 3 and the core 1.

In the crimp processing described above, when the crimp part 54 at theend of the sleeve portion 53 of the crimp retainer 5 is fitted into thecrimp groove 43, as the bending end is decreased in diameter to decreasethe circumferential length, the circumferential length has an extra.Hence, as shown in FIG. 8, in the crimp part 54 at the end of the sleeveportion 53, slits 55 extending from the end portion in the axialdirection are spaced regularly in the circumferential direction, theslits 55 absorb the extra of the circumferential length and thus thebending end inward in the radial direction reliably reaches the bottomof the crimp groove 43. As shown in FIG. 9, the slits 55 described abovehaving a small width may be arranged regularly, for example, at eightplaces in the circumferential direction, and as shown in FIG. 10, theslits 55 having a large width may be arranged regularly, for example, atfour places in the circumferential direction. FIGS. 9 and 10 show anexample of the width and the number of slits 55, and as necessary, thewidth and the number thereof are preferably changed and set.

Since the core 1 is structured by stacking, for example, a few hundredsof electromagnetic steel plates in the axial direction, the dimension ofthe core 1 in the stacked state in the axial direction is changed foreach stacked core 1. An error in the stacking dimension described abovecauses the position of the crimp retainer 5 in the axial direction to bechanged. Hence, with respect to the average stacking dimension of thecore 1, as shown in FIG. 6, the dimension of the crimp part 54 in theaxial direction is set such that the crimp part 54 of the crimp retainer5 straddles the crimp groove 43. In the setting described above, whenthe crimp part 54 is crimped from the outer circumference, as shown inFIG. 11(B), the crimp part 54 is engaged with the wall surface on theoutside of the crimp groove 43 in the axial direction, and the end ofthe crimp part 54 extends off the end portion of the crimp groove 43.

Then, when the dimension of the core 1 in the axial direction tends tobecome excessive, the position of the crimp part 54 of the crimpretainer 5 facing the crimp groove 43 is moved outwardly in the axialdirection, straddles the crimp groove 43 and is positioned furtheroutwardly in the axial direction. In this case, after the crimpprocessing, the crimp part 54 is engaged with the wall surface on theoutside of the crimp groove 43 in the axial direction and the end of thecrimp part 54 extends off the end portion of the crimp groove 43 morethan shown in FIG. 11(B).

Then, when the dimension of the core 1 in the axial direction tends tobecome insufficient, the position of the crimp part 54 of the crimpretainer 5 facing the crimp groove 43 is moved inwardly in the axialdirection, and the end of the crimp part 54 is arranged in an end of theregion of the crimp groove 43. In this case, after the crimp processing,the end of the crimp part 54 does not extend off the end portion of thecrimp groove 43 on the outside in the axial direction, and is, as shownin FIG. 11(A), engaged with the wall surface on the outside of the crimpgroove 43 in the axial direction.

In this way, it is possible to absorb the error in the stackingdimension of the core 1 by changing the bending state of the crimp part54 of the crimp retainer 5, and to apply a constant pre-pressure afterthe assembly (after the crimping) regardless of the error in thedimension of the core 1 in the axial direction.

In the present embodiment, it is possible to obtain the followingeffects.

(A) In the rotor shaft 4, the crimp groove 43 is formed in the outercircumferential portion of any one of the end plates 2 on the outside inthe circumferential direction. The one end plate 2 is located in theaxial direction by the inside end of the crimp retainer 5 in the axialdirection that is ring-shaped, that covers the crimp groove 43 of therotor shaft 4 to fit to the rotor shaft 4, that is fitted into the crimpgroove 43 of the rotor shaft 4 by crimping an outside portion in theaxial direction from an outer circumferential side, and that engageswith the wall surface of the crimp groove 43 on the outside in the axialdirection. In other words, the outside portion of the crimp retainer 5in the axial direction that presses onto the one end plate 2 and locatesit in the axial direction is crimped from the outer circumferentialside, is fitted into the crimp groove 43 of the rotor shaft 4 and isengaged with the wall surface of the crimp groove 43 on the outside inthe axial direction. Hence, the crimp retainer 5 engages with the wallsurface of the crimp groove 43 on the outside in the axial direction,and thus it is possible to locate the core 1 without coming off in theaxial direction, and its reaction acts on the one end plate 2 so as topress it in the axial direction, and thus it is possible to fix therotor shaft 4 with a predetermined pre-pressure applied to the core 1.

(B) The crimp retainer 5 includes, in the outside portion in the axialdirection crimped from the outer circumferential side to fit into thecrimp groove 43 of the rotor shaft 4, the slits 55 that extend from theexternal end portion in the axial direction to the inside in the axialdirection a predetermined angular space apart in the circumferentialdirection. In other words, when the crimp part 54 at the end of thesleeve portion 53 of the crimp retainer 5 of the crimp retainer 5 isfitted into the crimp groove 43, as the bending end is decreased indiameter to decrease the circumferential length, the circumferentiallength has an extra. However, since the crimp part 54 at the end of thesleeve portion 53 includes the slits 55 extending from the end portionin the axial direction a given space apart from each other in thecircumferential direction, the slits 55 absorb the extra of thecircumferential length and thus it is possible to make the bending endinward in the radial direction reliably reach the bottom of the crimpgroove 43.

(C) The crimp retainer 5 is, according to the position of the one endplate 2 in the axial direction in contact with the inside end in theaxial direction, crimped from the outer circumferential side and fittedinto the crimp groove 43 of the rotor shaft 4, and the position in theaxial direction engaging with the wall surface of the crimp groove 43 onthe outside in the axial direction is changed. In other words, since thecore 1 is structured by stacking, for example, a few hundreds ofelectromagnetic steel plates in the axial direction, the dimension inthe stacked state in the axial direction is changed for each stackedcore 1. An error in the stacking dimension described above causes theposition of the crimp retainer 5 in the axial direction to be changed.However, it is possible to absorb the change in the stacking dimensionof the core 1 by changing the bending state of the crimp part 54 of thecrimp retainer 5, and to apply a constant pre-pressure after theassembly (after the crimping) regardless of the error in the dimensionof the core 1 in the axial direction.

(D) The crimp retainer 5 includes, in the inside end in the axialdirection, the ring-shaped flange portion 52 extending in the radialdirection, and is brought into contact with the one end plate 2 by thering-shaped flange portion 52. In other words, in the ring-shapedportion 51 of the crimp retainer 5, its cross section is formed in theshape of an L with the flange portion 52 and the sleeve portion 53 suchthat shape rigidity, that is, bending rigidity with respect to the flatsurface perpendicular to the shaft is acquired by the sleeve portion 53and circular rigidity is acquired by the flange portion 52.

Second Embodiment

FIGS. 12 to 15 show a second embodiment of a rotor mechanism of arotating electrical machine according to the present invention. FIG. 12is a cross-sectional view of the rotor mechanism of the rotatingelectrical machine and FIG. 13 is a cross-sectional view of the crimpretainer. In the present embodiment, the ring-shaped portion of thecrimp retainer is changed into a spring structure that makes the flangeportion act in the axial direction, which is added to the firstembodiment. The same devices as in the first embodiment are identifiedwith the same symbols, and their description will be omitted orsimplified.

As shown in FIG. 13, the crimp retainer 5 of the present embodiment isformed with the ring-shaped portion 51 composed of a tapered flangeportion 56 and the ring-shaped sleeve portion 53 and the crimp part 54that protrudes from the sleeve portion 53 in the axial direction andthat is deformed by crimping. This crimp retainer 5 is formed of a highelastic material, for example, with high tensile strength steel sheetscommonly referred to as a “high-tension material.” The otherconfigurations are the same as in the first embodiment.

In the crimp retainer 5, a compression force is applied in the axialdirection, and thus the tapered flange portion 56 can be elasticallydeformed in such a direction that the taper angle is increased. In otherwords, as a compression force is added in the axial direction, the taperangle of the flange portion 56 is increased according to the compressionforce, and a dimension C without the compression in the axial directionshown in FIG. 13 being applied can be finally changed to a dimension Dobtained by raising the flange portion 56 in a vertical direction byelastic deformation, as shown in FIG. 14.

Then, the sleeve portion 53 and the crimp part 54 are formed to fit tothe outer circumference of the rotor shaft 4, and the sleeve portion 53is fitted to the rotor shaft 4 to be located in the radial directionwith respect to the rotor shaft 4.

In other words, the crimp retainer 5 is fitted to the rotor shaft 4 fromthe side of the crimp groove 43, and, as shown in FIG. 12, the end ofthe flange portion 56 is brought into contact with the side surface ofthe one end plate 2. Then, the sleeve portion 53 and the crimp part 54of the crimp retainer 5 are pressed from the side of the crimp retainer5 in the axial direction such that a constant pre-pressure (pre-load) isapplied to the end plate 3, the core 1 and the end plate 2 arrangedbetween the crimp retainer 5 and the protrusion portion 42 of the rotorshaft 4. Here, the flange portion 56 of the crimp retainer 5 iselastically deformed by the constant pre-pressure (pre-load) describedabove such that the taper angle is increased.

Thereafter, the crimp part 54 of the crimp retainer 5 is bent by crimpprocessing from the outer circumference into the crimp groove 43inwardly in the radial direction, thus is fitted into the crimp groove43 and is located with respect to the rotor shaft 4 in the axialdirection. Then, in the crimp retainer 5, the bending end of the crimppart 54 is pressed onto the wall surface of the bottom portion of thecrimp groove 43, is prevented from being moved outwardly in the axialdirection and is strutted, and thus it is possible to locate and fix thecrimp retainer 5 on the rotor shaft 4 with the pre-pressure kept appliedto both the end plates 2 and 3 and the core 1.

In this state, the amount of elastic deformation of the flange portion56 of the crimp retainer 5 is changed according to the position of theone end plate 2 in the axial direction. In other words, since the core 1is structured by stacking, for example, a few hundreds ofelectromagnetic steel plates in the axial direction, the dimension inthe stacked state in the axial direction is changed for each stackedcore 1. FIG. 15 shows a state where the position of the one end plate 2is changed to the side of the crimp retainer 5 caused by an error in thestacking dimension described above. However, in the present embodiment,the amount of elastic deformation of the flange portion 56 of the crimpretainer 5 is changed by the error in the stacking dimension describedabove. As described above, it is possible to absorb variations in thestacking dimension of the core 1 by changing the amount of elasticdeformation of the flange portion 56 of the crimp retainer 5, and toapply a constant pre-pressure after the assembly (after the crimping)regardless of the error in the dimension of the core 1 in the axialdirection.

In the present embodiment, it is possible to obtain the followingeffects in addition to the effects (A), (B) and (D) in the firstembodiment.

(E) The crimp retainer 5 includes, in the inside end in the axialdirection, the ring-shaped flange portion 56 extending in the radialdirection, the flange portion 56 is obliquely formed to be tapered suchthat its end is brought into contact with the one end plate 2 and thetapered inclination angle is changed according to the position of theone end plate 2 in the axial direction in contact with the inside end inthe axial direction. In other words, since the core 1 is structured bystacking, for example, a few hundreds of electromagnetic steel plates inthe axial direction, the dimension in the stacked state in the axialdirection is changed for each stacked core 1. However, the amount ofelastic deformation of the flange portion 56 of the crimp retainer 5 ischanged by the error in the stacking dimension described above. Asdescribed above, it is possible to absorb variations in the stackingdimension of the core 1 by changing the amount of elastic deformation ofthe flange portion 56 of the crimp retainer 5, and to apply a constantpre-pressure after the assembly (after the crimping) regardless of theerror in the dimension of the core 1 in the axial direction.

Although the embodiments of the present invention have been describedabove, the embodiments described above simply show an example of theapplication of the present invention, and the technical scope of thepresent invention is not intended to be limited to the specificconfigurations of the embodiments.

This application claims priority based on JP2011-45287, filed with theJapan Patent Office on Mar. 2, 2011 and JP2012-43774 filed with theJapan Patent Office on Feb. 29, 2012, the entire contents of which areincorporated into this specification by reference.

The invention claimed is:
 1. A rotor mechanism of a rotating electricalmachine that includes a core obtained by stacking a plurality ofdisc-shaped magnetic steel plates on an outer circumference of a rotorshaft and disc-shaped end plates arranged on both sides of the core inan axial direction, wherein the rotor shaft includes a crimp groove thatis formed, in a circumferential direction, in an outer circumferentialportion of any one of the end plates on an outside in the axialdirection, the one end plate is located in the axial direction by aninside end of a crimp retainer in the axial direction that isring-shaped, that covers the crimp groove of the rotor shaft to fit tothe rotor shaft, that is fitted into the crimp groove of the rotor shaftby crimping an outside portion in the axial direction from an outercircumferential side and that engages with a wall surface of the crimpgroove on the outside in the axial direction, and the crimp retainerincludes, in the outside portion in the axial direction, slits thatextend from an external end portion in the axial direction to an insidein the axial direction.
 2. The rotor mechanism of the rotatingelectrical machine according to claim 1, wherein the crimp retainerincludes, in the outside portion in the axial direction crimped from theouter circumferential side to fit into the crimp groove of the rotorshaft, slits that extend from an external end portion in the axialdirection to an inside in the axial direction a predetermined angularspace apart in the circumferential direction.
 3. The rotor mechanism ofthe rotating electrical machine according to claim 1, wherein the crimpretainer is, according to a position of the one end plate in the axialdirection in contact with the inside end in the axial direction, crimpedfrom the outer circumferential side and fitted into the crimp groove ofthe rotor shaft, and the position in the axial direction engaging withthe wall surface of the crimp groove on the outside in the axialdirection is changed.
 4. The rotor mechanism of the rotating electricalmachine according to claim 1, wherein the crimp retainer includes, inthe inside end in the axial direction, a ring-shaped flange portionextending in a radial direction, and is brought into contact with theone end plate by the ring-shaped flange portion.
 5. The rotor mechanismof the rotating electrical machine according to claim 1, wherein thecrimp retainer includes, in the inside end in the axial direction, aring-shaped flange portion extending in a radial direction, the flangeportion is obliquely formed to be tapered such that an end of the flangeportion is brought in contact with the one end plate and a taperedinclination angle is changed according to a position of the one endplate in the axial direction in contact with the inside end in the axialdirection.
 6. The rotor mechanism of the rotating electrical machineaccording to claim 1, wherein the crimp groove is formed around anentire circumference of the outer circumferential portion of the rotorshaft.
 7. A method of manufacturing a rotor mechanism of a rotatingelectrical machine that includes a core obtained by stacking a pluralityof disc-shaped magnetic steel plates on an outer circumference of arotor shaft and disc-shaped end plates arranged on both sides of thecore in an axial direction, wherein the rotor shaft includes a crimpgroove that is formed, in a circumferential direction, in an outercircumferential portion of any one of the end plates on an outside inthe axial direction, a ring-shaped crimp retainer including, in anoutside portion in the axial direction, slits that extend from anexternal end portion in the axial direction to an inside in the axialdirection is fitted to the rotor shaft to cover the crimp groove of therotor shaft, and an inside end of the crimp retainer in the axialdirection is pressed thereonto by applying a pre-pressure to the one endplate and an outside portion of the crimp retainer in the axialdirection is then crimped from an outer circumferential side to fit intothe crimp grove of the rotor shaft and is engaged with a wall surface ofthe crimp groove on an outside in the axial direction such that the oneend plate is located in the axial direction.